1. (a) Field of the Invention
This invention generally relates to a mechanism for releasably binding paired articles together. The invention includes short fabric tabs used to create looped sections on each sock, and a connector that extends through the loops to join the articles.
2. (b) Discussion of Known Art
My U.S. Pat. No. 5,740,558 teaches a method for connecting items such as socks together. However, discussions with sock manufacturers indicate the following criteria are key to developing an attachment system attractive to both manufacturers and consumers of paired items of apparel like socks:
1) Costs need to be minimized for any linking processes due to generally low margins on mated products.
2) Linking devices or systems need to be arranged to avoid skin contact and not create stiff uncomfortable areas on worn clothing. The linking system should be attached to the outside of a wearable item near the opening end in a manner that minimally impedes the stretchability of the top cuff of socks, gloves, etc.
3) A linking system should use a connecting process, which allows any pair of socks or other paired items to be bound together. This allows the industry to avoid the problem of left and right sock pairs, which would greatly complicate the pairing and packaging process.
4) Connectors should facilitate the drying process (including hang drying) by loosely binding the socks together so that drying air can flow to all parts of the sock.
Extensive testing by the inventor has uncovered additional criteria for a binding system:
A. The greater the attachment area over which the linking system can be spread on the paired items, the less likely the linking system is to damage the paired items when cleaning cycle or other forces are exerted on the linking system tending to pull the items apart through a connector.
B. The methods of attaching connecting elements to paired cloth items should be impervious to chemicals and temperatures encountered in the washing process for a reasonable user period. If cloth or other material tabs are used as part of a linking system, a method needs to be developed to prevent the tabs from fraying during wear, stress and repeated washing.
C. Systems linking socks together should have short relatively stiff linking systems to prevent the linking system from twisting and tangling around itself or adjacent laundered items.
D. The process of attaching a linking system to socks in the manufacturing environment is greatly simplified and made less expensive if non-cloth connecting components are added after the manufacturing process, either included in packaging or separately purchased and added by the consumer.
E. The attaching mechanisms need to stay with the socks when in use so as to be available whenever the paired items are removed from wear. Users will rarely search for a separate connector when removing socks.
F. Connectors need to be soft, somewhat flexible and have no sharp edges which can snag clothing, etc. during the wearing, washing or storing process.
G. The process for adding a linking system to socks should be done in the sock manufacturing plant and integrated into the process for maximum efficiency.
H. A consumer should be able to eliminate or deactivate a linking system from a pair of purchased socks if so desired without damaging the sock or other paired article.
In the following description, the inventor has noted where the above criteria were used with numbers/letters in brackets.
In his earlier U.S. Pat. No. 5,740,558, the inventor conceived a way to connect paired items together by attaching one end of tabs to each item, then putting connectors on the loose ends. Though this idea functioned well on paired items, the inventor found it difficult to attach tabs with imbedded connectors to socks and other paired items in a production environment. Machines that could spool, cut and position fabric tabs, could not currently handle tape with imbedded connectors such as snaps or thread tape through the closed loop end of some standard connectors. Expensive custom tooling would be necessary for this approach. Therefore, the intent, here, was to create a system that would bind a tab or xe2x80x9chandlexe2x80x9d to a paired item and allow for a connector to be addedxe2x80x94possibly by the consumerxe2x80x94after the tab-attachment process so that manufacture would be easier to accomplish with off-the-shelf equipment.
It has been discovered that the problems left unanswered by known art can be solved by providing a mechanism for releasably binding paired articles together. The invention consists of short fabric tabs, coated with a film adhesive on one side, adhesively-bonded at both ends to the top (or entry) outside edge of paired cloth items. The inventor has designed a mechanism for releasably binding paired articles together. The invention consists of short fabric tabs, coated with a film adhesive on one side, adhesively-bonded at both ends to the top (or entry) outside edge of paired cloth items.
The preferred orientation of the tabs is for the long side to point vertically down away from the opening or top so as to lay along the elastic ribs rather than across them. (FIG. 1) A flat plastic connector is looped through an unadhered wrinkle in the center of the tabs and then locked into itself to link the items together for storage, washing, etc. When the items are unpaired and in use, the connector is removed from the tab on the second paired item and locked in place around a single tab on the first.
The inventor discovered that if he bound the two ends of a tab to the paired item and left an open loop or wrinkle in the center, he could simplify the attachment process, create a handle for later attachment of a detachable connector, and also create an improved bond to the paired item. (FIG. 1). The improved two-point bond increased the bonding surface area, protected the item from tension on the tab by spreading out the load, prevented pealing of the connection by providing twin anchors to the paired item and had no left-right requirement for the attachable articles.
After testing the placement of the tabs, the inventor found that the best place to attach the handles was the outside edge of the entry area of the sock or paired item. This keeps the attachment away from skin as well as the interface between the wearer and footwear, etc. Further experimentation showed that the best way to attach a small, looped tab to a sock was with the long side of the tab down the outside neck of a sock. This minimized limitations to the stretchability at the entry point of socks and other paired apparel items.
Experimentation showed that the best material to attach to the paired items to create a xe2x80x9chandlexe2x80x9d would be a cloth fabric, preferably a synthetic because of synthetic""s strength, thin profile and low cost. The inventor initially tried stitching narrow, flexible, cloth tabs to the paired items. To minimize costs, he used 1xe2x80x3-2xe2x80x94long tabs cut from off-the-shelf xe2x85x9cxe2x80x94to xc2xcxe2x80x3 wide nylon or polyester fabric tape (or ribbon). These materials provided sufficient strength and surface area to bond strongly to socks, etc. and also spread out forces to prevent sock damage from tension on the tab. However, when using short tabs of cloth as a xe2x80x9chandlexe2x80x9d on the sock, he found that that even after stitching the ends to the sock, there could still be problems with the tab ends fraying and coming loose over time. He began to investigate techniques and materials for coating one side of the tabs with an adhesive material and using the adhesive to eliminate fraying as well as providing the binding process in place of stitching. Adhesives would allow the inventor to bind the full surface of the tab, excluding the loop, to the sock, thus improving load spreading and also eliminate fraying.
Tests with many adhesives showed that most adhesives would not survive repeated washings. However, eventually the inventor found a class of polyurethane (PU) and polyolefin (PO) adhesive films typified by the adhesive film sold by Minnesota Mining and Manufacturing as product xe2x80x9c3M 695xe2x80x9d film. These films were activated/attached through the application of a combination of heat and pressure. Through experimentation varying testing heat (temperature), time and pressure combinations and using 3-5 mil films, he was able to attach tabs to socks in a fashion which produced a bond that would withstand over 15 pounds of pull and still endure repeated washings with little noticeable deterioration, delamination or fraying. As a further advantage, the coated and adhered tabs stay soft and flexible, do not take on the feel of a hard plastic and do not fray. Another benefit of the film adhesives is that a customer can completely remove the tabs by heating them with an iron.
The double-bond design whereby the two ends of a tab are adhered to a sock with an unadhered center handle was most important in protecting the tab from stress that might peel the tab off the sock. Bonding the tab to cloth paired item entails applying heat to the outward facing side of the tab and driving the adhesive from the inward, coated side of the tab across to the sock. Using thin synthetic tape was critical in achieving fast, thorough heat penetration necessary for a good bond. Polyester and nylon tape have the capability of withstanding attachment temperatures over 300 degrees F. The choice of adhesives worked well because the melt temperatures were in the 250xc2x1 degrees F. range, well above anything encountered in a washer or dryer. (It may not be high enough to endure the temperatures applied to socks in the xe2x80x9cboardingxe2x80x9d process, however, which may limit the application point in a sock plant.) The adhesive proved impervious to the washing cycle for a reasonable useful life.
A further benefit of attaching tabs to socks with the heat/pressure sensitive adhesives like 3M 695 was that a consumer could remove or repair/reattach the tabs, if desired, with the aid of an iron generally set to the iron""s wool settingxe2x80x94lower if polypropylene used in the sock.
The final step was to determine a way to cut and attach the tabs to socks in a rapid and reliable fashion that would fit into the apparel manufacturing process. After extensive search, the inventor identified an Electro-Seal Mini-Coater machine with which he could coat the tab tape with adhesive film and an Electro-Seal Roll Feed Labeling Machine with which he could cut and heat/pressure attach the coated tape to paired items such as socks. Since more delicate fabrics, like polypropylene, are sensitive to heat, a cycle time of a few seconds is important in avoiding damage to the items during tab attachment.
The fast cycle time is achievable with the adhesives and labeling machines. The machines are also able to seal the tabs with the appropriate unadhered loop in the middle.
During his search for the tab materials and attachment process, the inventor also began to experiment with possible connectors which could be used by the user to link the paired items with looped tabs together. In one embodyment, he chose plastics for its strength, ease of forming and benignness for use on the body. He concentrated on thermoplastics and thermosets such as Polyamides (Nylon), i-ID polyethylene (HOPE) and polypropylene (PP), PP in thicknesses of 20-35 mils being the preferred material for cost, finish and durability.
There are two options for linking the tabs together: 1) to use two connectors, one attached to each item""s tab that then can be connected and disconnected to each other, and 2) to use a single connector which remains on one paired item""s tab when worn and can be connected to the second when pairing is required. In his notebook, he designed many connectors and found the system would work with a range of connectors from tied strings to key rings. The connector design, which he customized for this application following option 2 above (referred to as the S-link), is shown in FIGS. 2, 3, 4 and 5 with the following characteristics:
1. Stiff wide section makes it easy to thread through the tabs and loops of items to be connected. Easy for user to grasp when threading and unthreading.
2. Loosely holds paired items together to facilitate drying. Facilitates hang drying.
3. Flat, wide structure of shaft holds anchor perpendicular to eyelet after insertion to prevent accidental disengagement and resists exorbitant twisting.
4. Broad head on anchor is designed for easy grasping when connecting and edges prevent accidental disengagement.
5. Key-hole like eyelet keeps anchor from floating in slot in a motion that would increase the chance of accidental disengagement.
6. As a flat plastic part, the punch dies required to make this part are cheap to manufacture and allow many design adjustments for different applications and requirements.
7. Locking mechanism is easy to manipulate by feel (no need to see it), which is helpful for sight-limited users or when used in low light conditions.
8. As a single piece that locks two items with together or compresses an item, it allows the connected items to be manufactured without having to pair right and left.
9. Flexible plastic construction and rounded edges minimize the possibility of abrasions if compressed against the skin of a user when left on the paired item when worn.
10. Easily connected and disconnected from sock so can be eliminated if user does not want to keep connector on one of pair while wearing connected items.
11. Since it is added to the connected items such as socks after manufacture addition of tabs, it simplifies the application of the tabs and reduces sock-tab manufacturing and application costs and complexity.
12. Design (FIG. 3) with hole and slot tends to prevent accidental disengagement and also allows manufacture of slot with looser tolerances in ratio of anchor width to keyhole width.
13. If manufactured with several holes connected by slits, it allows the connector to be used at multiple tightnesses or loop diameters. (FIG. 4)
14. The process for attaching the tabs can be carried out at a number of sites in a sock mill, etc. as well as away from the mill as an after production add on. For socks, appropriate production line locations are:
a. With the label machine attached to the bottom side of a knitting machine, especially on with a toe-closing apparatus, so that as the toe is elevated while stitching, the open cuff could be grasped by the label machine to attach the tab. In this case, adhesive melt points must be high enough to survive the boarding process.
b. Just after the boarding process so that as socks are pulled off the boards, the open ends can be introduced to the label machine for tab attachment.
c. Just after socks are paired for uniform length, each open end can be presented to the label machine for tab attachment.
d. Just prior or just after the socks toes are stitched or possibly during stitching with a mechanism for grabbing the open end as designed for the stitching machines.
With the tabs attached, socks and other connectable items can be packaged for sale in the conventional way with the connector stapled to the packaging, threaded into one of the tabs on a sock or sold in separate packages to consumers.
It should also be understood that while the above and other advantages and results of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combinations and elements as herein described, and more particularly defined by the appended claims, it should be clearly understood that changes in the precise embodiments of the herein disclosed invention are meant to be included within the scope of the claims, except insofar as they may be precluded by the prior art.